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New genetics testing at CHEO is making it possible for Ontarians with inherited heart conditions to attain more complete testing results that could help manage their disease and minimize the chance of death.

CHEO will now be the only Molecular Genetics Diagnostic Laboratory in Canada designated by the Ministry of Health to provide this testing for cardiomyopathies.

"What this means is that the laboratory can develop a very high level of expertise for this type of testing in Ontario and pave a way for personalized medicine in the future," said Dr. Olga Jarinova, associate head of CHEO's Molecular Genetic's Diagnostic Lab.

The testing, which officially started July 1, analyzes 27 different genes that can cause hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy in both children and adults.

Hypertrophic cardiomyopathy, the most common form, happens when the heart muscle cells enlarge and cause the walls of the ventricle to thicken, which can block blood flow out of the ventricle.

Arrhythmogenic right ventricular cardiomyopathy, however, is rare and happens when the muscle tissue on the right ventricle dies, interrupts the heart's electrical signals and causes arrhythmias.

"What we're hoping with this testing is that we can find a genetic explanation in people who have these diseases," said Caitlin Chisholm, genetic counsellor at CHEO. "Sometimes this can help clarify their diagnosis, it can help guide their treatment but it's also really helpful for family members who have a condition and want the others in their family tested for it as well."

The first step in testing is for the patient to provide a sample, typically a blood sample.

Next, DNA is extracted from the sample and multiplied. The sample is then ready for critical analysis which is done by using the new technique called Next Generation Sequencing, or a machine called NextSeq500. This allows the technicians to look at the patient's DNA to find any abnormalities.

This new technology makes it possible to screen 12 patients simultaneously for 45 different genes in 24 hours.

The results are then analyzed and put together in a report which is then sent off to the physician.

The testing process, said Chisholm, takes about a week. However, from the time blood is taken from the patient until a diagnosis can take up to two months.

BY THE NUMBERS

- 700 children and young people die in Canada each year from sudden cardiac arrest

- An estimated 400 families a year in Ontario are referred for genetic tests to help diagnose the cause of a heart condition or identify which relatives may be at risk

- CHEO estimates that the hospital will be sending 1,000 samples for testing for their patients alone

New genetics testing at CHEO could save lives

New genetics testing at CHEO is making it possible for Ontarians with inherited heart conditions to attain more complete testing results that could help manage their disease and minimize the chance of death.

CHEO will now be the only Molecular Genetics Diagnostic Laboratory in Canada designated by the Ministry of Health to provide this testing for cardiomyopathies.